Sheet feeding apparatus



Nov. 23, 1943. H. L. KABEL SHEET FEEDING APPARATUS,

Filed April 29, 1941 2 Sheets-Sheet 1 INVENTOR HANS L.KABEL BY j E AORNEY Nov. 23, 1943. H. L. KABEL SHEET FEEDING APPARATUS Eiled April 29, 1941 2 Sheets-Sheet 2 INVENTOR HANS L. KAaEL B A; iORNEY A. 3 A F% u 00 M? W m 1 j W a Patented Nov. 1943 snsa'r FEEDING mm'rus nan, L. Kabel, Modesto, cum, assignor to The Borden Company, New York, N.

tion of New Jersey Y., a comra- Application April 29, isinseriai No. 390,883 2 Claims. ('01. 271-32) This invention relates to apparatus for feeding sheet material.

In the operation of metal working machines handling sheet material, it is usually desirable to supply the sheets'rapidly and one at a time. For example, sheets of tinplate have to be fed rapidly and uniformly to can body or similar machines in order to have these machines operate efliciently. For this purpose, the sheets of material are frequently arranged in a vertical stack and a feeding arrangement is provided for withdrawing one sheet at a time from this stack and feeding it to the machine that forms it into a'can or performs other operations upon it.

In magazine feeding devices ofthis type, however, it is very important to avoid the feeding of more than one sheet at a time. When two or more sheets stick together and are fed to the forming or operating machine, jamming of the machine is apt to occur, requiring stoppage of the entire machine. If the forming machine is not actually damaged, there is at least a substantial waste of sheet material. It is particularly difficult to prevent two or more sheets of fiat sheet material from sticking together in a. vertical magazine due to the smooth surfaces of the sheets and the weight of sheets in the magazine. This problem is further increased by the development of higher feeding speeds requiring in some cases the accurate and efllcient feeding of sheets from a magazine at the rate of several hundred a minute. Y

One object of my invention is to provide apparatus for feeding sheet material from a magazine so that no more than one sheet is taken from the magazine at a time and so that the sheet selected is not nicked or otherwise damaged during the feeding operation.

Another object of the invention is to provide magazine feeding apparatus for sheet metal which is readily adjustable for different sizes of sheets and which is sufiiciently flexible to feed only one sheet at a time even though the sheets vary slightly from each other in size.

Other objects will be apparent from a description of the preferred embodiment of my invention in the accompanying drawings, in which Figure 1 is avertical sectional view through approximately the center of a magazine feeding device for sheet metal.

Figure 2 is a vertical sectional view through the apparatus, taken on the offset line 2-2 of Fig. 1.

apparatus in different positions during thei'eeding operation.

Figure 5 is a sectional view, taken on the line 55 of Fig. 1.

Figure 6 is a perspective view of one 01' the stripper members.

Figure '7 is a sectional view, taken on the line 1-,-'I of Fig. 6.

The embodiment of the invention illustrated in .the drawings may be used for feeding sheets to any suitable machine such as the feeding of sheet tinplate into a can body machine, into a cutter for cutting the sheets to sizes, or into machines for performing various other operations upon the sheet material. The actual formingor operating machine is not illustrated in the drawings since it forms no' part of my invention.

Numeral l0 indicates the vertical guide columns, of which there may be four, forming a magazine to hold a stack of sheets I I. The guide columns l0 may be either fixed in position or adjustable to accommodate sheets of different sizes, as will be-understood by those skilled in the art. A ledge lllamay be provided extending between two of the guide columns ill to support one side of the stack of sheets, and brackets lllb having rounded ends may be fixed to the other two of the columns ill to support the other two corners of the stack of sheets ll. The ledge Illa and brackets lllb thus support the weight of the stac Immediately below the stack of sheets I l are a pair of vertically reciprocating suction cups l2 supported at the upper ends of rods I3 which in turn are fixed to the block ll. These vacuum cups I2 may be connected by the flexible hose l2a to a vacuum pump with a suitable timing mechanism (not shown) for alternately applying and relieving the vacuum, as is customary with feeding devices of this type. The block I 4 may be carried by the slide I5 adapted to slide up and down between the inclined guides I 6. Movement may be imparted to the block M by means of a link I! having its upper end pivotally connected to the block 14 by means of the pin l8. The lower end of the link I! is pivotally connected by the pin I!) to one side of the flywheel 20 that rotates with the shaft 2|. Any suitable means (not shown) may be employed for rotating shaft 2|.

A horizontal slide 22 having an enlarged end 22a is supported for reciprocation on the table 23 and is moved back and forth by the link 24 pivotally connected at one end by means of the pin 28 to the depending lug 28 fixed to the bottom of the slide 22. The other end of the link 24 is pivotally connected by means of a pin 21 to the rocker arm 28, which is rocked back and'forth about the shaft 28 by any suitable means (not shown).

At the other side of the magazine opposite the slide 22, a pair of positively driven rolls 38 are disposed for feeding sheets pulled from the magazine onto the continuous belt conveyor 3!, which carries these sheets ,one at a time in properly spaced relation into a can body, or other type of forming machine.

Each ,pair of guide columns I8 is connected together by a bar 32 held in place by bolts or other suitable means. One or more brackets 33 may be clamped or otherwise secured on each of the bars 32 with their legs 34 and 35 straddling the bars 32. These brackets 33 maybe clamped securely to the bars 32 in any desired position by means of the bolts 38 acting as set screws. The legs 35 of the brackets 33 extend up to form the upwardly extending arms 31, and stripper members 38 are attached to and resiliently supported by these arms 31.

together at their top by straps 4| provided with suitable openings 42. The stripper members 33 may be mounted on the arms 31 of the brackets 33 by means of bolts 43 extending through openings in the arms 31, the openings 42, and coil springs 44' held in place by means of the nuts 45.

It will be apparent that by loosening the bolts 36, these stripper members 38 may be mounted in a vertical position or inclined in either direction at will, or moved to any suitable locations on the bars 32. The coil springs 44 serve to provide a resilient mounting for the stripper members 38 permitting them to be pressed laterally outward from the magazine, or permitting tilting of them in any direction against the compression of the springs 44. The resistance or these springs 44 may be readily varied by tightening or loosening the nuts 45.

The serrations 48 on the inclined surfaces of the stripper fingers 38 preferably are rounded somewhat, as illustrated, to avoid nicking or otherwise damaging the edges of thesheets pulled down over them. Also, these serrations are prefcolumns l8 with the lowest sheet of this stack resting on the shelf I80 and the pair of corner brackets 18b. Rotation of the shaft 2| and flywheel 28 causes the link I! to reciprocate, moving the slide l5, block l4, rods l3 and vacuum cups l2 up and down in the direction of the inclined guides I8.

them apart unless the suction between the individual sheets is first broken. The vacuum cups l2 travel downwardly, however, at an inclined and there is a certain amount of slippage between the sheet fastened to the vacuum cups and those immediately above it, which assists in breaking this suction between the sheets. Also, as soon as the sheet to be fed and those that have been pulled.

free of the magazine supports strike the stripper fingers 38, the inwardly and downwardly inclined surfaces of the stripper fingers cause the sheets to flex and the serrations 48 catch the edges of the sheets that have been pulled from the ,bottom of the stack. By the time that the lowermost sheet has been pulled clear of the stripper fingers 38, therefore, it has been positively separated from the next sheet above it and only one sheet is carried down through the rest of the downward stroke of the vacuum cups 12.

By reason of the inclined movement of the vacuum cups and their support, one edge of the sheet attached thereto is brought to a position where it is just touching the revolving rolls 38. And by this stage in the operation, the vacuum in the cups l2 has been broken by the timing mechanism previously referred to.

The slide 22 by this time has been moved a short distance towards the rolls 38 by the link 24 and rocker 28. The front and 22a of this slide 22 strikes one edge of the sheet that has been pulled down by the vacuum cups. 12, thus forcing the opposite edge of the sheet between the rolls 38 which pick it up and quickly transfer it to the continuous belt conveyor 3|.

While this sheet is being transferred to the conveyor 3| by the rolls 38, the vacuum cups l2 vacuum cups l2 again reach the bottom of the stack ll, they fasten onto the lowermost sheet and repeat the operation. The angle of the teeth or serrations 48 on the stripper fingers 38 is such that a sheet supported between them may be easily pushed up against the bottom ofthe stack As the vacuum cups i2 reach the top of this stroke, suitable timing mechanism (not shown) supplies vacuum through the flexible hose l2a to the vacuum cups l2, which are thus fastened to the central portion of the lowermost sheet in the stack I I. As the vacuum cups l2 are pulled downwardly, the corners of the lowermost sheet, and usually of two or three sheets thereabove,

' a II by the vacuum cups l2 before they start their downward stroke.

A particular advantage of the resiliently supported stripper fingers 38 in preventing the feeding of more than one sheet at a time',-is-that these stripper fingers may be tilted or inclined at different angles to the vertical by simply loosening the bolts 38 and adjusting the positions of the brackets 33 on the bars 32. It has been found desirable to have the serrations 48 on the stripper finger surfaces somewhat rounded at the corners and inclined to ermit any sheets that are pulled down below the bottom of the stack to be easily pushed upwards again by the vacuum cups I 2. This avoids nicking or otherwise dam- I2 may be moved through a plain vertical path or pulled downwardly at another angle than the one shown, and the stripper fingers may be correspondingly adjusted. Furthermore, it is not necessary to have the stripper fingers inclined at the same angle as the angle of movement or the vacuum cups l2 because satisfactory operation of the apparatus is Obtained with the stripper fingers 39 vertically disposed whether the vacuum cups i2 move in a vertical or an inclined path.

By this invention, it has been found that the operation of the feeding mechanism can be speeded up to feed several hundred sheets per minute without any damage to the sheets or to the machine being fed.

The invention has been described with particular reference to sheet tinplate but it is to be understood that the invention is well adapted to the feeding of other metal sheets as well as nonmetallic sheet materials.

The terms and expressions which I have empioyed are used as terms of description and not of limitation, and I have no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but recognize that various modifications are possible within the scope of the invention claimed.

I claim:

1. Sheet material feeding apparatus comprising a magazine for holding a stack of sheets, vacuum operated gripping means for pulling the lowermost sheet in the stack downwardly at an incline to the vertical, and yieldable stripper fingers having inwardly and downwardly inclined serrated surfaces for engaging the edges of such a sheet and separating it from the sheets thereabove.

2. Apparatus as defined in claim 1 in which the stripper finger surfaces are inclined at substantially the same angle as the angle of movement of the vacuum operated gripping means.

HANS L. KABEL. 

